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Biomedical subjects

H Mogami

Publications and source records attributed to H Mogami.

At least 127 records · Page 7Linked to original sources
PubMed1987

Pathology of brain parenchyma in meningeal carcinomatosis; immunohistochemical study with astroprotein (GFAP) and tubulin.

Effects of leptomeningeal tumor on the brain parenchyma was studied by the immunohistochemical method with astroprotein (GFAP) and tubulin in a rat model of meningeal carcinomatosis. Thickening of subpial glial lining (external glial layer) and hypertrophy of subpial astrocytes, detected by the antiserum to GFAP, was the early sign of parenchymal involvement. The glial lining was continuous as far as the tumor cells were confined to the subarachnoid space, however, penetration of tumor cells into subpial brain was associated with disruption of the glial lining. Speculative role of this lining in preventing the tumor cell to infiltrate into brain tissue was discussed. In contrast to the prominent immunohistochemical changes in astrocytes, neuronal tubulin immunoreactivity was not altered even in the late stage of the disease. The present study demonstrated that the leptomeningeal dissemination of tumor cells did cause pathologic change in brain parenchyma as was evidenced by the reactive change of astrocytes. However, the preserved immunoreaction for tubulin suggested that the nerve cell damage was not severe even at the advanced stage of the disease.

Animals↗
PubMed1987

Simulation and experimental study of respiratory motion effect on image quality of single photon emission computed tomography (SPECT).

The effect of respiratory motion on the image quality of single photon emission computed tomography (SPECT) was investigated by computer simulation and experimentation. In the computer simulation, the phantom was assumed to be cylindrical with a uniform background and a spherical cold or hot spot. To simulate respiratory motion, a cyclic linear motion parallel to the axis of rotation of a gamma camera was assumed. The contrast in the transaxial images was calculated for various respiratory amplitudes and its dependence on lesion size and object contrast was investigated. In the experiments, a moving phantom was used to simulate respiratory motion. The simulation and the experimental results were in good agreement within the range of statistical error. The effect on the lesion detectability was investigated using receiver operating characteristics (ROC) analysis, and a method for correcting respiratory motion was devised.

Computer Simulation↗
PubMed1987

A comparative study of attenuation correction algorithms in single photon emission computed tomography (SPECT).

A computer based simulation method was developed to assess the relative effectiveness and availability of various attenuation compensation algorithms in single photon emission computed tomography (SPECT). The effect of the nonuniformity of attenuation coefficient distribution in the body, the errors in determining a body contour and the statistical noise on reconstruction accuracy and the computation time in using the algorithms were studied. The algorithms were classified into three groups: precorrection, post correction and iterative correction methods. Furthermore, a hybrid method was devised by combining several methods. This study will be useful for understanding the characteristics, limitations and strengths of the algorithms and searching for a practical correction method for photon attenuation in SPECT.

Algorithms↗
PubMed1987

Autoradiographic study of regional protein synthesis in focal cerebral ischemia with TCA wash and image subtraction techniques.

The standard biochemical method of trichloracetic acid (TCA) wash and the image processing technique were combined to differentiate and visualize the distributions of polypeptide-incorporated and unincorporated tracers in an autoradiographic study of regional protein synthesis. The validity of applying TCA wash procedures to cryostat sections was considered by histologic and chemical evaluations. For the autoradiographic study of in vivo protein synthesis, a tracer dose of L-[14C]valine was administered 30 min after occlusion of the posterior communicating artery in gerbils. Images of total (polypeptide-incorporated and unincorporated) radioactivity and of polypeptide-incorporated radioactivity were obtained from an identical cryostat section before and after TCA wash. The polypeptide-unincorporated radioactivity image was produced with an image processing system by subtracting pixel by pixel the polypeptide-incorporated radioactivity from the total radioactivity. The present study clearly demonstrated that in spite of the sufficient delivery of tracer amino acids, the polypeptide synthesis was completely lost in the ischemic focus. Free tracer was markedly accumulated in the brain adjacent to the ischemic focus. This kind of autoradiographic technique seems to be indispensible in studying the topographical complexity of the altered protein metabolism in the pathologic brain.

Animals↗
PubMed1987

Primary myxoma in the pituitary fossa: case report.

A case of primary myxoma in the pituitary fossa is described. The tumor presented as an intrasellar and suprasellar mass and was successfully removed during a transsphenoidal operation. It was verified as a myxoma by histopathological studies, and there was no evidence that it was a metastasis. This is thought to be the first report of this tumor occurring in the pituitary fossa.

Adult↗
PubMed1987

Glioblastoma after radiotherapy for craniopharyngioma: case report.

A 6-year-old girl developed a glioblastoma in the basal ganglia and brain stem 5 years after surgical excision and local irradiation (5460 cGy) for craniopharyngioma. Clinical and histological details are presented, and the literature on radiation-induced gliomas is reviewed.

Basal Ganglia↗
PubMed1987

Malignant recurrence of childhood cerebellar astrocytoma: case report.

A 15-year-old boy developed a glioblastoma in a cerebellar hemisphere 7 years after surgical excision and local irradiation of a pilocytic astrocytoma in the cerebellar vermis. Clinical and histopathological details are presented, and the literature on late malignant recurrence of childhood cerebellar astrocytoma is reviewed.

Adolescent↗
PubMed1987

Intraoperative measurement of cortical blood flow and its CO2 response in childhood moyamoya disease.

Cortical blood flow was monitored during craniotomy for bypass surgery to treat childhood moyamoya disease. The patients were hyperventilated, and changes in cortical surface blood flow were detected by a heat clearance method with plate type thermocouple probes. End-tidal CO2 was monitored during hyperventilation to avoid excessive reduction of CO2. There were three types of blood flow responses to hyperventilation: simple reduction, prolonged reduction, and increase. Simple reduction was noted in four cases and was related to constriction of basal and ethmoidal moyamoya vessels. Prolonged reduction was noted in three cases and was related to excessive constriction of basal moyamoya vessels. Increase was noted in four cases and was related to increase in blood flow from cranial vault moyamoya vessels. The results indicate that the basal moyamoya vessels are constricted by hyperventilation. This may be the cause of ischemic symptoms provoked by hyperventilation.

Adolescent↗
PubMed1987

Modulation in vitro and in vivo of ACNU resistance in a subline of C6 glioma with reserpine.

Reserpine enhanced in vitro the cytotoxicity of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) in both the C6 glioma and its ACNU-resistant subline, C6/ACNU. Reserpine also enhanced the chemotherapeutic effect of ACNU in C6/ACNU-bearing (C6/ACNU-meningeal gliomatosis) rats, in which ACNU resistance could be modulated by combined ACNU and reserpine therapy. When 10 microM reserpine was added to ACNU in culture, the concentration of drug required for 50% inhibition of cell growth (IC50) of ACNU for C6/ACNU cells decreased to the level of that for C6 cells. When 20 microM reserpine was added to the culture, intracellular uptake of ACNU in C6/ACNU cells increased further and the efflux of the drug from the cells decreased. In in vivo experiments in rats, combined chemotherapy with ACNU (1 mg/kg) and reserpine (250 micrograms/kg) by intrathecal injection significantly increased the life span of the rats as compared to results with ACNU chemotherapy alone. The enhanced cytotoxicity of ACNU in ACNU-resistant glioma cells in vitro and in vivo may be explained by the increase of intracellular concentration of ACNU resulting from the inhibition of ACNU efflux from the resistant cells by reserpine. It was concluded that ACNU resistance could be modulated in vitro and in vivo by combined therapy with ACNU and reserpine.

Animals↗
PubMed1987

Adoptive immunotherapy of human meningeal gliomatosis and carcinomatosis with LAK cells and recombinant interleukin-2.

Previous in vitro studies have demonstrated that peripheral blood lymphocytes activated with recombinant interleukin-2 (rIL-2) generated cells that were lytic for fresh autologous tumor cells but not for normal lymphocytes or lymphoblasts. Adoptive transfer of autologous lymphokine-activated killer (LAK) cells induced in vitro with rIL-2 was used in two patients: one with meningeal gliomatosis and the other with meningeal carcinomatosis. The adoptive transfer of LAK cells was very effective in reducing the clinical symptoms and signs, and in eliminating the malignant cells from the cerebrospinal fluid. Thus, this therapy is an attractive approach for the treatment of malignant tumors that have poor immunogenicity and are insensitive to several anti-cancer agents, and for patients with severe immunosuppressive conditions induced by repeated radiation therapy or chemotherapy.

Adult↗
PubMed1987

Primary cerebellar hemorrhage. Quadrigeminal cistern obliteration on CT scans as a predictor of outcome.

The authors studied a consecutive series of 75 patients with cerebellar hemorrhage diagnosed by computerized tomography (CT) scanning, and assessed the relationship of outcome to the CT appearance of the quadrigeminal cistern, which in some cases was obliterated by rostral displacement of the vermis resulting from the cerebellar mass. Obliteration of the quadrigeminal cisterns was classified on the CT scans into three grades: normal (Grade I), compressed (Grade II), or absent (Grade III). There were 43 patients with Grade I, 16 with Grade II, and 16 with Grade III cisterns. Of the 75 patients, 38 (88.4%) of those with Grade I, 11 (68.8%) of those with Grade II, and none of those with Grade III cisterns returned to their previous activities at 6 months or more after onset. A Grade I cistern predicted a good outcome whether the hematoma was evacuated or not, as long as obstructive hydrocephalus, if present, was relieved early. However, a Grade II cistern was not predictive of a good outcome unless the hematoma was evacuated within 48 hours after onset of the hemorrhage. A Grade III cistern invariably predicted an unfavorable outcome. It is concluded that the CT grade of quadrigeminal cistern obliteration is an accurate indicator of outcome and is highly useful in selecting appropriate treatment for patients with cerebellar hemorrhage.

Adult↗
PubMed1987

[Changes in protein and RNA synthesis following acute hindbrain ischemia].

Protein and RNA synthesis of the brain is affected by focal transient ischemia. Protein synthesis is depressed by the depletion of energy metabolism during ischemia, and its recovery following recirculation is slower than restoration of energy metabolism. On the other hand, RNA synthesis is more tolerable to ischemia than protein synthesis. Present study has designed to evaluate changes of protein and RNA synthesis of the brain after ischemia. We used a hindbrain ischemia model of gerbils, and quantitative autoradiography was applied for estimation of regional protein and RNA synthesis. The model was made by occluding the basilar artery for 15 minutes and recirculating afterwards. 14C-valine was used as a tracer for protein synthesis. In the ischemic group, protein synthesis was inhibited extremely in the medial thalamus, inferior colliculus, gray matter of the pons and midbrain, and cerebellum, RNA synthesis by salvage pathway was evaluated using tracer doses of 14C-uridine. It increased 1.6-2.4 folds of sham controls in the thalamus, and gray matter of the pons and midbrain. De novo synthesis of RNA was evaluated using 14C-carbamoylphosphate and 14C-NaHCO3. 14C-NaHCO3 antoradiogram showed inhibition of tracer incorporation into RNA and protein fraction in the ischemic lesions. 14C-carbamoylphosphate autoradiogram showed no significant change. These results indicate that protein synthesis is inhibited after ischemia but response of RNA synthesis to ischemia is not uniform. De novo synthesis of RNA is inhibited following ischemia, but RNA synthesis by salvage pathway increases in the ischemic lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

[Treatment of rat glioma with a beta-adrenergic agonist and a phosphodiesterase inhibitor in vivo].

Rat C 6 glioma is known to possess a beta-adrenergic receptor with which intracellular cyclic adenosine monophosphate (cAMP) levels are altered to control cell growth in vitro. In order to study the effect of beta-adrenergic agonist, isoproterenol, in growth-inhibitory action upon C 6 glioma cells, subcutaneous tumor models and meningeal gliomatisis (MG) models as a brain tumor model have been exposed to the treatment of isoproterenol. Growth of subcutaneous tumor was suppressed by the treatment of the drug, and the survival time of MG rats was prolonged by the intrathecal (i. t.) injection of isoproterenol. The addition of papaverine, phosphodiesterase inhibitor, to the treatment schedule augmented the growth-inhibitory effect of isoproterenol. Therefore, it is concluded that the survival time of the brain tumor models could be prolonged through the inhibition of the growth of C 6 glioma cells by such drugs as those which elevate intracellular cAMP levels.

Animals↗
PubMed1987

[Treatment of a rat meningeal gliomatosis model with neocarzinostatin].

Meningeal gliomatosis (MG), pathologically, is caused by the diffuse dissemination or infiltration of glioma cells in the subarachnoid space, for which an effective, systematic treatment has not been contrived. Although, in the case of malignant leptomeningeal tumor, in general, intrathecal chemotherapy with such anticancer drugs as methotrexate and cytosine arabinoside (Ara-C) has been applied, the effect of this kind of treatment is limited, especially on MG. Therefore, the development of a new type of treatment is urgently needed. According to recent reports, neocarzinostatin (NCS) has been disclosed to have a strong cytocidal effect on glioma cells instead of injuring normal glia cells, and the intrathecal injection of NCS is suggested to be effective on MG. In order to evaluate the efficacy of intrathecal treatment with NCS on MG, a rat MG model using C 6 glioma cells has been produced and intrathecal chemotherapy with NCS was performed on this MG model. In MG rats which were treated intrathecally with NCS (1 microgram/kg) 1 day after tumor inoculation, the survival time was significantly prolonged by this treatment, where % ILS was 52.1%. Furthermore, it was more significantly prolonged with 10 micrograms/kg NCS, where 108.5% of % ILS was obtained. Contrary to these effects, this prolongation of the survival time of MG rats by the treatment with NCS showed a tendency to decrease in MG rats treated with NCS 3 days after tumor inoculation. No chemotherapeutic effect was observed in MG rats treated with even 100 micrograms/kg NCS 5 days after tumor inoculation. In conclusion, intrathecal chemotherapy with a low dose of NCS was proved to be effective in the early stages of MG.

Animals↗
PubMed1987

[Usefulness of caerulein in suppressing post-TAE complications of the gallbladder].

While transcatheter hepatic arterial embolization (TAE) has been extensively performed as a form of treatment for nonresectable malignant hepatic tumors, complications, such as abdominal pain, fever or leukocytosis due to gallbladder infarction by embolic materials frequently occur and have not yet been overcome. We devised a new procedure for reducing the incidence of gallbladder infarction by administering caerulein prior to TAE. Between 1984 and 1986, 63 patients with hepatocellular carcinoma were treated by TAE with the use of Gelfoam. These patients were divided into 3 groups. Fourteen patients underwent TAE in which the tip of the catheter was placed in the right hepatic artery distal to the origin of the cystic artery (group A). In the other patients the tip of the catheter was placed proximal to the origin of the cystic artery; 40 patients were not treated by caerulein (group B); 9 patients were administered caerulein 20 micrograms intramuscularly 15 to 30 minutes prior to TAE. The incidence of complications after TAE, such as abdominal pain, fever over 38 degrees C, leukocytosis and ultrasonographical abnormalities of the gallbladder was compared in these 3 groups. The results showed that in group C (TAE after administration of caerulein), the incidence of complications was significantly decreased compared with group B(TAE without caerulein). The authors suggest that post-TAE infarction of the gallbladder is effectively diminished by contracting it with caerulein.

Carcinoma, Hepatocellular↗
PubMed1987

[Immunohistochemical study of human brain tumors with vimentin and astroprotein (GFAP)].

Distributions of two different subclasses of intermediate filaments, vimentin and glial filaments, were studied immunohistochemically in human brain tumors using specific antiserum to each protein subunit, vimentin and astroprotein (GFAP), Surgical specimens (5 meningiomas, 4 ependymomas, 5 benign astrocytomas, 5 anaplastic astrocytomas and 7 glioblastomas) were fixed in 95% ethanol or ethanol-acidic acid (95:5) and embedded in paraffin Avidin biotin peroxidase-complex (ABC) method (Vectastain) was carried out on 6 microns-thick paraffin sections. All meningioma cells were negative for astroprotein (GFAP) and positive for vimentin. Ependymoma cells showed various patterns of immunoreaction for astroprotein (GFAP) but were invariably positive for vimentin. In benign astrocytomas, many cells (or cell body and processes) were positive for astroprotein (GFAP). Immunoreaction for vimentin was, however, less frequent and intense. In anaplastic astrocytomas, population of astroprotein (GFAP)-positive cells decreased and vimentin-positive cells increased. Astroprotein (GFAP)-positive cells were further decreased in glioblastomas and the population of vimentin-positive cells varied among tissues. The present study suggests that the anaplastic change of astrocytoma cells were associated with decreased expression of glial filaments and increased expression of vimentin filaments. It was also suggests that the expression of both intermediate filaments may be suppressed in highly-malignant glial tumor cells.

Astrocytoma↗